Means for filling lead presses in the manufacture of cable sheaths



Inventor Carl A. Pier-c C. A. PIERCY Filed July 2, 1938 CO GAS MEANS FOR FILLING LEAD PRESSES IN THE MANUFACTURE OF CABLE SHEATHS STEAM Jan. 30, 1940.

Attorney.

Jan, 30, 1940. c. A. PIERCY 2,188,794

MEANS FOR FILLING LEAD PRESSES IN THE MANUFACTURE OF CABLE SHEATHS Filed July 2, 1938 2 Sheets-Sheet 2 Inventor: Car-l A.Fier- 7/ (I, AM

Patented Jan. 1940 UNITED STATES MEANS FOR FILLING LEAD PRESSES IN THE MANUFACTURE OF CABLE SHEATHS Carl A. Piercy, Ballston Lake, N. Y., assignor to General Electric Company, a corporation of New York Application July 2, 1938, Serial No. 217,294

17 Claims.

The usual form of lead press employed in the manufacture of sheaths for cables comprises a cylinder open at the upper end and having means or controlling its temperature, a die block and dies receiving plastic lead from the cylinder for extruding it around the insulated conductor or conductors of the cable, and a ram for applying extruding pressure to the lead after it has been cooled to a determined degree. Such cylinders are charged or filled by pouring molten lead through the upper open end thereof from a melting kettle.

As is well known, molten lead at the temperatures employed oxidizes very rapidly when exposed to air, and, unless special means are employed to prevent it, the oxides so formed during the pouring operation, especially between successive charges of the cylinder, are carried through the press and die block into the finished sheath. The molten lead entering the cylinder 'in a stream spatters to a greater or lesser extent and due to the spattering, the oxidation of the lead is thereby substantially increased. In this connection, it is to be noted that the lead is heated to such a high temperature that it flows much like water. The oxides mentioned are very objectionable as they cause imperfections of various kinds in the sheath, and in many casesare found to be present for a considerable longitudinally extending area of the sheath. This is particularly noticeable when an area of the sheath is composed partly of the old charge and partly of the new. In this connection, it should be remembered that in nearly every case several charges of the cylinder are required to sheath a single length of cable. The ram on its working stroke does not force all of the lead out of the cylinder and thus there remains what is termed the residual charge. As soon as the ram is raised above the cylinder opening preparatory to the pouring or filling operation, air freely enters the cylinder with the result of oxidizing the upper exposed surface of the residual chargeas well as the incoming charge of molten lead. The hot charge of lead under ordinary conditions of pouring fails fully to melt the surface of the residual charge with the result that any oxide present between the old charge and the new is carried with the lead into the'finished sheath and results in imperfections. To avoid spattering it has been proposed to pour hot lead into the cylinder. from the melting kettle through a tube, the lower end of which terminates at or about the top of the residual charge, and in this particular follows the processes used in the casting of ingots of steel and other metals where the inclusion of air and other gases is objectionable. In one instance of which I have knowledge, the entire filling tube has to be moved about within the cylinder so that small areas of the residual charge 5 are successively acted upon by the incoming molten lead. In this case, the tube is entirely open at its bottom end and in addition has numerous small openings or ports through which the hot lead issues in a purely radial direction. 10 This arrangement, beside being open to the objectionable featureof having manually to manipulate the tube from its upper end in order to move the lower end, is open to the further objection that air may be entrained with the lead and 15 because of the unrestricted opening or orifice at the tube end the tube is not completely and promptly filled with lead at the start of the pouring operation and there exists in the tube a certain amount 'of air which to some extent is bound 20 to oxidize the hot lead. In addition to the foregoing, the arrangement described necessitates an operator whose position at or over the cylinder exposes him to the high temperatures necessary in cable sheathing operations. In another in- 25 stance, it has been proposed to use a filling tube that terminates in a curved end located in close proximity to the wall of the cylinder, the said end having a single discharge orifice. In the last mentioned instance, the hot lead of the new 30 charge cannot fully melt the surface of the residual charge, and to the extent that it does not determine the amount of oxides which are ultimately carried into the finished sheath during the extrusion or pressing operation.

My invention is directed to the type of lead press where the cylinder is filled with molten lead from the bottom end thereof by means of a stationary depending filling tube, and has for its object the provision of improved ways and means 40 whereby the objections above noted are overcome and the formation of oxides largely prevented and whereby such oxides as are formed are removed from the lead prior to extrusion. Stated more specifically, my invention has for its ob- 45 ject the provision of improved filling means for cable lead presses wherein during filling operations, the formation of oxides is more adequately prevented than heretofore, also the provision of improved means for delivering the incoming 5o charge of molten lead in such manner as to. adequately melt the top part of the residual charge and also the shim located in the space between the ram and the cylinder .wall and cause any oxides thereon, due to exposure to air when the ram is retracted or otherwise to be released and later caused to collect in a mass and to rise to the top of the charge so that they may be readily removed by suitable means at the end of the filling operation.

For a consideration of what I believe to be novel and my invention, attention is directed to the accompanying description and the claims appended thereto.

In the attached drawings which are illustrative of my invention, Fig. 1 is a view in side elevation of a cable sheathing press and melting kettle; Fig. 2 is a plan view thereof with certain upper parts of the press removed; Fig. 3 is a view in elevation of means for connecting the cylinder filling tube to the discharge spout of the melting kettle; Fig. 4 is a plan view of said means; Fig. 5 is a capping means for the discharge spout; Fig. 6 is a view partly in section of the filling tube and nozzle attached thereto; Fig. '7 is a partial view of the flooding ring located on top of the cylinder; Fig. 8 is a sectionalview of the upper part of the cylinder showing means for directing burning hydrogen into the cylinder and protecting the entrance thereof when the ram is retracted; Fig. 9 is a view of a part of the cylinder with burners for directing burning gases against the exposed surface of the hot lead contained in the flooding ring; Fig. 10 illustrates a modified form of melting kettle; Fig. 11 is a plan view of one of the burners in which oxide reducing gas is employed, and Fig, 12 is a plan view of the inside part of the discharging nozzle at the lower end of the filling tube.

Referring to Fig. 1, l0 indicates the cylinder of a lead press having the usual or suitable means for controlling its temperature, and II the opening leading from the sheath forming dies and through which lead tubing or the cable and its,

sheath of lead passes to the outside. Directly above the cylinder is a ram I2, the bottom surface of which is made slightly conical so that air cannot be trapped between it and the molten charge but on the contrary air will be pushed by the beveled surface or cone outwardly to the edges of the ram and hence prevented from being trapped and forced by the ram into the lead. The ram is actuated by a piston l3 contained in a cylinder M to which water or other liquid under high pressure is admitted subject to suitable controlling valves. The cylinder is supported by cross-members I ia that in turn are supported by heavy vertical column 15. Molten lead at a temperature of 400 to 410 C. is supplied to the press cylinder by a melting kettle of suitable construc-.

tion. The one illustrated comprises a pct 16 shown in dotted lines and is heated by any suitable means. Inside of the pot is a vertical partition l1 and between it and the left-hand wall of the pot is a chamber into which pigs of lead to be melted are introduced. The level of the molten lead varies of course from time to time, but the dotted line l8 indicates what may be termed a suitable operating level. Since the partition does not extend fully to the bottom of the pot, molten lead is free to fiow from the left-hand compartment into the one in the center. 0n the righthand side is a second vertical partition H! which does not extend-quite to the bottom of the pot. From the chamber thus formed extends a spout 20 that in turn is connected to the press cylinder filling tube. The left-hand chamber has a sealing cover 2| supporting a steam pipe 22; the

ceived are discharged through an outlet 25.

When the lead is at the desired temperature and the press ready to receive a charge, steam is admitted to the left-hand compartment from the pipe 22 the pressure of which forces the molten lead into the center and right-hand chambers to raise the level thereof and thence into the main spout 20. Extending from the main spout is a discharge spout 26 terminating in a well rounded end as shown in Fig. 3 to which the filling tube 21 is connected aswill be explained later. The filling tube is divided into'three principal parts which are united by couplings 28. 'The purpose of the arrangement is to permit the parts to be separated and thoroughly cleaned after a predetermined number of operations. In this manner, any appreciable accumulation of oxides is prevented. At the lower end the filling tube is provided with a nozzle 29 of special construction which will be described later.

As it is necessary to insert the tube into the press cylinder for filling it and to remove the tube before the ram I2 descends, the following means are provided: Supported by a pair of the columns I5 is a horizontal shaft 30, and secured thereto is a lever 3| of bell-crank shape, the outer end of which is pivotally connected to a fiat steel plate 32, Fig. 1, secured to the under side of one section of the filling tube 21 and projecting into the space between parts of the lever. nected to the elbow of the lever 3| bya pin-andslot connection 33, the purpose of which is to hold the upper end of the tube 21 in position for easy connection to the spout 26 as well as to hold it in stationary operative position. The parts at this point are very hot and hence not easily handled by an operator. On one end of the shaft 30 is a hand wheel 50 by means of which the bellcrank lever 3| is caused to move the filling tube into and out of the cylinder of the press. The dotted lines indicate the position of the fillin tube in its retracted or idle position,

On top of the cylinder is secured what for convenience is called a flooding ring 38, Fig. 2, which during the charging operation is filled to the upper level thereof and constitutes an additional means for preventing the entrance of oxides into the cylinder. Located within the ring is a plurality of radial partitions 39, three being shown in the present invention, which terminate in close proximity to the wall of the ram when in its lowered position. The partitions are secured to the ring and are tapered or beveled from the bottom thereof to the top, the latter rising a short distance above the top level of the ring. The partitions are for the' purpose of dividing the mass of chilledlead into removable segments after the ram I2 has started its downward movement and entered the top of the cylinder. As the ram descends, the apex of its conical end first engages the lead in the flooding ring The plate is conforced radially outward. The descending ram by its displacement may cause more or less hot metal to spill over the top wall of the ring. By having the partitions rise somewhat above the level of the flooding ring and projecta short distance beyond its periphery, any hot metal spilling over the ring is likewise divided into segments which facilitates subsequent removal thereof after the metal is chilled or hardened. The ram is made slightly smaller in diameter than the cylinder to compensate for differencesin expansion of the two bodies, and as a result there exists in the operation of the press a relatively thin shim 40, Fig. 7, which as the ram descends is displaced upwardly with the result of pushing the segments upwardly, the tapered partitions 39 facilitating this action. At this stage in the operation, it may be stated that the metal in the flooding ring has become chilled or hardened. The force exerted by the shim is sufficient to force the segmental metal pieces 4| in the flooding ring upwardly, as best shown in Fig. 7. In practice the effect of the shims is more noticeable in the region of the ram than at the wall of the ring. The tapered walls of the partitions and the fact that the inner wall of the flooding ring is also beveled or tapered, as shown at 42, facilitate this action. After the ram has entered the cylinder, the segmental pieces 4| may be readily pried out of the ring by a suitable tool and later put into a kettle for remelting. Obviously the removal of a unitary ring of metal around the ram would be much more difficult than when in segmental pieces.

The ram according to standard practice is slightly smaller'than the bore of the cylinder'to take care of expansion of the ram when heated. As a result, a thin shim of varying shape and size is left between the ram and the cylinder wall. Irrespective of the shape and size of the shim, some portion thereof will remain as usual in the cylinder after the ram is removed, the exposed surface of which oxidizes if and when air has access thereto. In my improved construction, the shim so remaining is quickly melted by the incoming swirling hot charge of molten metal as it rises vertically from the bottom. The swirling action of the charge of' hot metal is due to the action of the nozzle at the bottom of the filling tube as will appear later.

Referring to Figs. 3 and 4 which illustrate a suitable means for uniting the lower end of the spout 26 and the filling tube, the lower end of the spout has an enlarged head 44 with a rounded under surface which cooperates with a correspondingly shaped seat in the head 45 attached to the upper end of the filling tube 21. To the spout is secured a bracket 46 having downwardly extending ears upon which are pivoted a pair of bell-crank levers 41, the lower ends thereof engaging the under side of the head 45. Each lever at its upper end has a swiveled nut 48 through which extends a rod 49-having right and lefthand screw threads located within the nuts. On the rod is a small hand whel 50 for turning it to cause the lower ends of the bellcrank levers to engage or disengage the head 45 to cause clamping of the heads or permit separation thereof. To ensure equal movements of the levers, the rod is centrally supported by an upright member having a fork engaging a shouldered groove formed in the threaded rod.

In order to prevent air from entering the main spout 26 when the steam pressure in the lefthand chamber is released, a temporary cap or cover 52 shown in Fig. 5 is employed. It is clamped against the lower end of the spout 26 by the same means employed for clamping the filling tube 21. After the filling tube is disconnected and before the cap 52 can be applied, there will be an escape of non-oxidizing gas from the pipe 24 and the right-hand chamber, the effect of which is to prevent oxidation of any lead which may be clinging to the inner wall of the spout. The gas also prevents the entrance of air into the spout after the cap is removed and prior to the clamping of the filling tube to the spout. There is also a flow of such gas through the spout 26 and filling tube 21 into the lower end of the press cylinder prior to the admission of the molten lead from the kettle. The admission of gas as thus described is controlled by a valve 53 in the gas pipe leading into the right-hand chamber of the melting pot. In this connection, it is to to be noted that the levelof the hot lead in the pot is below the level of the spout except when steam or other gas under suitably high pressure is admitted by the pipe 22 to the left-hand compartment of the melting pot. If desired, an additional or even the sole supply of non-oxidizing or oxide reducing gas for the filling tube may be admitted thereto by a gas pipe 24 attached to the spout, subject to the control of a suitable valve. To the lower end of the filling tube is secured a nozzle 29 which is an important feature of my invention since reliance is placed thereon to melt the upper part of the residual and solidified charge remaining in the press cylinder after the ram has completed its working stroke. The residual charge is indicated in Fig. 1 by the dotted line 54. The lowest part of the nozzle is desirably located a short distance, for example of the order of one-fourth of an inch, above the level of the residual charge so that the incoming hot metal has full access to said charge. In some cases, however, the lowest part of the nozzle may rest upon the charge. By suitably melting the upper part of the residual charge, the oxides formed therein or thereon by air entering the cylinder when the ram is raised above it or from other sources, are released and caused to float on the surface of the incoming charge from which they can be removed by skimming. The nozzle may be made in one piece but since it is important to keep the surfaces of the nozzle well cleaned, it is desirable for that reason to make the nozzle of such character that it can be taken apart.

The lower end of the tube 21 as shown in Fig. 6 is screw threaded and mounted thereon is a conical head 55 having an internal positioning shoulder engaging the lower end of the tube. The external surface of the head is made smooth and all projections such as shoulders are desirably avoided so that the nozzle when removed avoids disturbingthe hot lead as completely as possible, and also to prevent the formation of gas pockets. The inside surface 56 of the head is likewise made conical, enlarging from the top to the bottom, and located therein is a member 51 which is also made conical, its wall being separated by a uniform distance from the surface 56. Both surfaces 56 and 51 are made smooth so as not to offer undue restriction to the flow of hot metal. On the member is a plurality of vanes 58, of which four are shown as an example in Fig. 12. The main consideration is to provide smooth easy passages for the hot metal with a minimum amount of friction. The vanes extend downwardly from approximately the top of the surface 56 to the bottom of the member and are in contact with the conical wall so as to form definite passages for the hot metal. The vanes are also curved from end to end so as to discharge the hot metal in streams in a direction tangential or approximately tangential to the axis of the nozzle to cause a swirling, rotary motion of the passage of the hot metal.

hot lead issues from the nozzle with considerable velocity. The combination of the streams effectively melts the top part of the residual charge,

and to such an extent that a slug composed of a new and an old charge shows complete union without the presence of oxides. It will be observed that the vanes are all inclined in the same direction, have the same radial depth, and that the side surfaces thereof are parallel to each other although curved from end to end, the curvature resulting in a better angle of discharge for producing the swirling action of the hot lead in the cylinder than would be the case if the vanes were straight and only downwardly inclined. It is also to be noted from Fig. 12 that the vanes for a portion of their respective lengths are in overlapping relation, the effect of which is to form walls that give definite direction to the lead streams before they leave the nozzle. The arrangement of the vanes is such as to cause a quick and complete scrubbing action by the molten lead over the entire surface of the residual charge and this in turn is followed by the rapid melting of the upper part of the residual charge. In general, it may be stated that the smoother the walls of the nozzle and the freer the entrance of the hot lead into the nozzle, the better will be the final results. The vanes are integral with the cone member 51 and each has a projection or eariill near its lower end fitting into a radial notch 6| formed in the lower edge of the head 55. The vane member as a whole is held in place by a smooth surfaced nut 62 threaded to the head. The upper edge of the nut engages an external shoulder on the head and at the point of engagement the parts are of the same diameter, thus providing a smooth exterior, the purpose being to prevent undue disturbance of the metal in the cylinder and the trapping of gas as the tube and nozzle are removed after the filling operation. It is also to be noted that the underside of the vane carrying member is also coned, the purpose being to prevent any trapping of air in the hot metal at the beginning of the filling operation. Any air in the space directly under the member will be forced radially outward by the beveled or inclined surface 63 as the level of the molten charge rises. From what has been stated above it will be noted that the tube 21 performs the double function of supplying gas to the cylinder at the start of each operation and of supplying molten metal thereto thereafter.

In Fig. 8 is illustrated a burner 64 made in two parts each extending approximately around onehalf of the ram l2. The burner is desirably supplied with hydrogen gas which as it burns reduces oxides formed on the surface of the pool of molten lead contained in the flooding ring 38 before the ram begins its downward or workin stroke. In practice, the supply of gas to the burner is turned on full head before the ram starts it outward stroke from the cylinder. The parts of the half burner are each pivotally supported by hinge pins 65, as shown in Fig. 9, so

in the latter a low vacuum which tends to such the flames further into the cylinder. Above the burner 64 it is desirable to mount a second burner 66 for hydrogen, the flames of which are directed downwardly against that portion of the pool of hot lead in the flooding ring directly under the ram and over the cylinder. The second burner, best shown in Fig. 11, isgcarried by a flat plate 61 which has a supporting arm 68 swiveled on the post 69, there being a suitable passageway 10 for the gas. Since the second burner when in service is directly under the ram, it must of course be swung to one side before the ram begins its working stroke. The burner is given the horse-shoe shape indicated by the dotted lines in Fig. 11 in order to provide a large surface area. The plate is cut away at 61 to permit the insertion and removal of the filling tube. Itis also provided with a curved stop 61' to ensure the proper positioning of the burner.

Experience in the actual manufacture of lead pipes and cable sheaths, including the making of careful tests, has demonstrated that melting of the upper part of the'old charge effectively takes place. so that no joint or line of cleavage is discernible even with a powerful microscope. Also that the swirling or rotary action of the body of lead within the cylinder due to the vanes in the nozzle causes a considerable portion of the incoming hot charge of lead to be carried outwardly toward the cylinder wall, and that the oxides and other impurities being lighter in weight are not so moved but on the contrary collect in the neighborhood of the filling tube, where centrifugal effects are at a minimum, in

the form of a sponge-like substance, the sponge floating at the top of the charge and rising with it as its level rises. The sponge remains in the region of the axis of the cylinder due to the fact that the, swirling action initiated by the nozzle continues during the entire filling of the cylinder. ing ring are filled, the sponge may readily be removed as a unit by a scoop or other tool. There is suflicient adhesion of the particles in the sponge to hold the sponge intact. Analysis of the so-called sponge shows that it commonly contains oxides of the order of seven per cent by weight of the complete sponge, is quite porous and easily broken.

In addition to the means above described for reducing oxides, it is also desirable to skim the surface of the hot lead in the flooding ring prior to the downward stroke of the ram because not lead oxidizes very rapidly. This skimming is particularly important when for any reason a slight delay occurs in the successive operations previously described.

The molten lead should enter the cylinder under a considerable head pressure if the best results are to be obtained. This may be done by suitably elevating the melting kettle with respect to the cylinder where this is feasible but where it is not, a melting pot of suitable construction may be employed where the lead is confined to one properly sealed chamber, in-

stead of three as shown in Fig. '1, in which case.

a non-oxidizing gas under determined pressure is applied to the exposed surface of the molten lead for forcing the lead from the kettle. By

When the cylinder and the floodchanging th gas pressure, the swirling and rotary action of the body of hot lead in the cylinder may be controlled. By observation, it can be determined if the head pressure is sufiicient to obtain the desired swirling and rotary action of the molten lead in the cylinder. If the head pressure is too low, there will be a tendency noticeable after'the cylinder is partly full for a small amount of oxide floating'on the charge to move laterally into contact with the cylinder wall and be retained thereby as the level rises. This, howevendoes not affect the sponge which floats near the axis of the cylinder at all times.

In Fig. 10 is illustrated a melting pot of the type just above mentioned where H indicates the outer casing of the pot, 12 the pipe carried by the cover 13 for supplying a neutral or nonoxidizing gas to the chamber of the pot under a pressure regulated by the valve 14, and 15 the outlet spout.

The nozzle at the end of filling tube while acting freely to discharge the hot lead nevertheless offers some restriction to outward flow and in so doing permits the tube to be completely filled from the bottom' to the top which in effect results in a solid column of highly heated lead. For this purpose, the spout 26 should be large enough to freely supply the necessaryamount of lead. As previously stated, non-oxidizing gas from the pipe 24 flows through the spout 20 into the filling tube and thence into the cylinder before the filling operation begins. This means then that the first part of the charge entering the filling tube is not exposed to air but on the contrary is exposedonly to a nonoxidizing gas which aflords additional protection for the lead.

Reference has been made herein to lead and such designation is intended to be broad enough to include lead as such or other metals suitable for making sheaths for cables and this whether the lead or other metals are pure or containingredients intended to change the characteristics of the finished product. I

What I claim as new and desire to secure 'by Letters Patent in the United States is:

l. A lead press comprising a cylinder that retains a residual. charge after each operation, a ram, and extruding die means in combination with a flooding ring mounted on top of the cylinder of larger diameter than the ram, a removable filling tube connected at one end to a source of molten metal and extending through the ring into the cylinder and terminating at or in proximity to the residual charge therein for discharging molten metal downwardly and laterally against the charge, means for moving the tube into and out of the cylinder for each charge and holding it in a fixed position while in use, and removable burner means'located between the plane of the lower end of the ram and the top of the pool of molten lead in the flooding ring and supplied with a combustible gas for reducing oxide forming on the top of the pool after the filling tube is removed.

2. A lead press comprising a cylinder that retains a residual charge after each operation, a ram, and extruding die means in combination with a flooding ring mounted on top 'of the cylinder of larger diameter than the ram, a removable filling tube connected at one end to a source of molten metal and extending through the ring into the cylinder and terminating in proximity to the residual charge therein for discharging molten metal downwardly and laterally against the surface thereof, means for moving the tube into and out of the cylinder and holding it in a fixed positon while in use, a pair of segmental ring burners located directly above the pool of molten lead in the flooding ring defining an opening through which the ram is free to pass, pivotal supports for the parts of the burner, a second removable burner located between the segmental burner and the lower end of the ram, a support for the second burner permitting it to be swung out from under the ram, the burners being supplied with combustible gas, the flames of which play on the molten lead in the flooding ring and reduce oxides on the surface thereof, those of the second ring being directed downwardly on that portion of the pool directly over the cylinder.

3. A lead press comprising a cylinder and ram, in combination with a removable filling tube extending from a source of supply of molten lead into the cylinder and terminating near the residual charge therein, and a nozzle on the end of the filling tube within the cylinder comprising a head having a plurality of downwardly inclined laterally extending passages for the molten metal which due to the pressure of the incoming charge directs it against the residual charge in a manner to melt the surface thereof and also impart a swirling rotary motion to the body of lead, thereby'causing the heavier parts of the incoming charge to travel toward the cylinder walls and permitting the oxides liberated from the residual charge by the melting thereof to gather in the form of a sponge near the axis of the cylinder and rise to the top thereof as the level of the charge rises.

4. A lead press comprising .a-cylinder and ram, in combination with a filling tube extending from a source of supply of molten lead into the cylinder and terminating near the residual charge therein, and a nozzle on the end of the filling tube within the cylinder comprising a head having an axial passage and a series of downwardly inclined, laterally extending vanes defining passages for the molten metal, the vanes causing -a swirling rotary motion of the body of lead tube for the cylinder thereof in which there remains a residual charge after each operation of the ram, the tube having a nozzle at its discharge end adjacent the hardened residual charge, the nozzle comprising a conical member arranged with the large end at the bottom, vanes on the outer surface of the member which are downwardly and laterally inclined with respect to the axis of the member, a head having a conical surface surrounding the member, the vanes and the conical surface defining passages "for directingthe' discharge of molten metal, and

means for detachably securing the member inside of the head. I

6. A lead press vhavinga cylinder.and ram, there being a residual hardened. body of" metal in the cylinder after each working stroke of the ram, in combination with a stationary filling tube for the cylinder, and a nozzle at the lower end of the tube in spaced relation to the residual charge, the nozzle comprising a head secured to the lower end of the tube having a downwardly diverging inner wall, a detachable conical member located in the head having a through central opening of restricted size for directing a stream of hot metal perpendicularly against the residual charge to partially melt it, vanes on the member which engage the inner wall of the member, the vanes being downwardly and laterally inclined for causing the hot metal to cause a swirling action of the body of hot metal as it is discharged, and a means engaging the lower ends of the vanes for detachably securing the member within the head.

7. A lead press having a cylinder and ram, there being a residual hardened body of metal in the cylinder after each Working stroke of the ram, in combination with a stationary filling tube for the cylinder, and a nozzle at the lower end of the tube in spaced relation to the residual charge, the nozzle comprising a head secured to the lower end of the tube having downwardly and laterally discharging passages for molten metal, the under surface of the nozzle beingv beveled upwardly from its axis so as to prevent accumulation of gas directly under it by forcing such gas to travel laterally toward the outer edge of the nozzle as the level of the charge rises.

8. A lead press comprising a cylinder that retains a residual charge after each operation, a ,ram and extruding dies, in combination with a filling tube of substantial cross-sectional area adapted to be connected with a source of molten lead at its upper end, a nozzle at its lower end located in proximity to the residual charge, the nozzle having downwardly and laterally inclined passages to cause a swirling action of the lead as it enters the cylinder and flows over the residualcharge, the combined cross-sectional areas of the passages being less than that of the filling tube so that in the filling operation there is a solid column of molten lead above the nozzle and the presence of air pockets is thereby avoided.

9. In combination, a press having a cylinder, and a ram, a sealed melting kettle, a tube receiving molten metal from the kettle, the tube extending into the cylinder, a nozzle on, the lower end of the tube adjacent theresidual charge of plastic metal in the cylinder having downwardly 'and laterally inclined passages for discharging molten metal over the surface of the residual charge, and means supplying gas under pressure to the interior of the kettle to force molten metal through the tube and outof the nozzle under a pressure greater than that due to gravity-.- r

A 10-."A nozzle for discharging; molten metal,

,. comprising a headr having a downwardly-,di

"verging "inner wall and notches, a detachable member located therein in spaced relation: to: the

tawall having 'a conical eripheral surface,-downiwardly'. inclined curved" vanes on the member elocated in -the space between it andv wall, ears 7 Ion the vanes fitting into the notchesnand; preventing the memben from turning within the head, and means for holding the member in place :and the ears in the-notches. I Y

ji /11. A lead presscomprising a cylinderthat .retains a residual charge after each operation; a and extruding die means in combination with a flooding ring mounted on top of the cylinder of larger diameter than the ram, a removable filling tube connected at one end to a source of molten metal and extending through the ring intothe cylinder and terminating at or in proximity to the residual charge therein for discharging molten metal downwardly and laterally against the charge, means for moving the tube into and out of the cylinder for each charge and holding it in a fixed position while in use, and a means located between the plane of the lower end of the ram and the top of the pool of molten lead in the flooding ring for directing non-oxidizing gas downwardly against the surface of the metal in the pool to protect it from the efi'ects of air.

12. A press comprising a cylinder, 2, ram for extruding metal therefrom, a source of molten metal, a tube detachably connected to the source and terminating within the cylinder near the bottom thereof for filling the cylinder with molten metal from the bottom thereof, and a controllable source of supply for admitting nonoxidizing gas to the filling tube and cylinder prior to the admission of molten metal thereto to remove air therefrom.

13. In combination, a press comprising a vertical cylinder, a power operated ram for extruding plastic metal therefrom, a pot of molten metal which is protected from exposure to air, a removable tube for filling the cylinder connected to the pot at one end in a manner to prevent the admission of air thereto, and at the other end terminating within the cylinder near the residual charge contained therein, a means for admitting non-oxidizing gas to the filling tube and cylinder prior to the admission of molten metal thereto, and means for increasing molten metal passing vthrough the tube and issuing from the end thereof within the cylinder to a value greater than that due to the hydrostatic head of the molten metal. I

14. In combination, apress comprising a cylinder, a ram for extruding metal therefrom, a melting pot, a filling tube connected at one the velocity. ofthe end to the pot for receiving molten metal there-,

Y oxides on the residual-parts of the prior charge.

15. In combination, a press comprising a ,fiilingthe cylinderrwith molten metal-from the bottom thereof, a nozzle attached to the end:

of the tube within the cylinder and located adjacentthe residual charge thereinytheiiozzle im- 1 parting a swirling movementto the issuing metal and also to the body of: metalasit rises in the -cylinder,'anda "-'supply elastic fluid acting on. the metal within the tube-"undersuch positive pressure as to 'increase the veiocity of flow of fne'tal from the nozzle to a greater-value: than that due. w' the'hydrostatichead of the metal contained in =the' 'filling tube?- -16. A cable press comprising a cylinder, a ram,

cylinder, a ram for extruding metal from the cylinder, a melting pot, a tube connected atone end to' the pot to-receive molten metal therefrom and -terminating,,,w-ithin the cylinder, for

axis upwardly toward the edges to prevent accumulation of gas thereunder by forcing it laterally outward from the axis of the ram at the beginning of its working stroke, die means receivingplastic metal from the cylinder, means for moving the ram, a flooding ring mounted on the top of the cylinder directly under the ram for 1 receiving metal overflowing from the cylinder and also that displaced by the ram on its descending stroke, a removable tube extending downwardly through the flooding ring into the cylinder through which the cylinder and'ring are filled from the bottom, and a nozzle at the bottom end of the tube in proximity to the re? sidual charge in the cylinder. for imparting a swirling motion to the hot metal in both the cylinder and ring as it rises and fills them, thereby causing the oxides liberated by the incoming hot metal to collect in sponge form about the axis of the cylinder and ring and rise to the top of the charge of molten metal in the ring from which it may be removed.

1'7. An extrusion press for metal comprising a cylinder and ramsin combination with a melting pot for the metal, a filling tube detachably connected to the pot and receiving molten metal therefrom, the tube extending downwardly into the cylinder to a region adjacent the residual charge therein, and a means for supporting the tube and also for inserting it into and removing it from the cylinder comprising a member attached to the tube between its ends for supporting, guiding and moving it when detached from the pot, a shaft on which the member is mounted, and means for turning the shaft to move the tube into and out of the cylinder.

CARL A. PIERCY. 

